To get this answer, you add up the corresponding coordinates.
The x coordinates add to -4+4 = 0
The y coordinates add to 7+1 = 8
The z coordinates add to 2+(-3) = -1
Another way to express this is to consider
u = (a,b,c)
v = (d,e,f)
which add to u+v = (a+d,b+e,c+f)
